Various medical procedures require transillumination of the skin or other human tissue. For example, premature babies often require intravenous (IV) feeding. In order to determine the most appropriate location to insert the IV device, the child's skin is transilluminated, typically by a conventional fiberoptic cable. Similarly, for older individuals, certain surgical operations and other medical procedures require the physician to initially determine the location of the patient's veins and other blood vessels in order to avoid these areas when cutting through the skin or other tissue. Usually, the tissue in question is examined by first introducing a scope into the body through a cannula inserted through the tissue. The scope is directed toward the tissue. The physician transilluminates the tissue using a standard fiberoptic cable. This enables blood vessels to be detected by the scope.
Conventional fiberoptic cables exhibit a serious drawback when used in the above-described manner. In order to properly transilluminate the skin or other tissue, the light projecting end of the cable typically must be placed directly against or in close proximity with the outer surface of the skin. As a result, the light is focused onto the skin with an intensity that is apt to burn the patient. Premature infants and other small children have particularly sensitive skin which is highly susceptible to such burns.
Standard transillumination techniques exhibit several other shortcomings. For example, none of the known devices enables the physician or other person manipulating the distal end of the fiberoptic cable to adjust the intensity of light used for transillumination. Such light adjustments must be performed by an assistant at the illuminator. This results in delays, possible miscommunications and intensity misadjustments. Likewise, there is no transilluminator presently available which enables the physician or other personnel manipulating the instrument to quickly and reliably switch the light on and off through the cable. This procedure again must be performed at the illuminator.